X-ray crystal analyzer is widely used in x-ray wavelength dispersed detection system, such as in wavelength dispersed x-ray fluorescence system (WDXRF), x-ray emission spectroscopy system (XES), fluorescence model x-ray absorption spectroscopy system (XAS) and extended x-ray fine structure system (EXFS). All these kind of crystal analyzers are based on Bragg's diffraction law. They are normally made from single crystals, or multiple layers. In order to increase detecting efficiency, they are machined and bent in one dimension or two dimensions with some shapes. And analyzers curved in two dimensions are much better than in one dimension both in energy resolution, efficiency and lower background, but more difficulty. Such crystal analyzers can be employed in the Rowland circle with either the Johann or Johansson geometries, for wavelength-specific focusing of x-rays in diffraction way. For applications, a radius of curvature of one meter is typically required.
Normally, a quite lot of crystal analyzers are made in bending crystal wafers to curved substrates by glue or anodic bonding method. Due to strong strain force from crystal wafers in bending, it is always quite difficult to get good energy resolution in two dimension bent analyzers. Although there exist dicing-bent spherical crystal analyzers, the efficiency is always reduced due to a partial crystal area diced off. So, two dimension bent crystal analyzer in full size with less strain is a big advantage to x-ray spectrometers.